CLEAVAGE OF PROTEINS 55 



more the autolytic enzymes persist in animals 

 from which the pancreas has been removed. We 

 see from these facts that protein tissues disinte- 

 grate normally in the animal body without the 

 formation of poisonous products. It must be 

 admitted that in certain pathological conditions, 

 such as acute yellow atrophy of the liver and in 

 phosphorus poisoning, autolysis proceeds with 

 harmful rapidity and becomes at least a highly 

 destructive process. 



It has been suggested that the autolytic en- 

 zymes are constituents of the blood and are 

 generally distributed through the body by this 

 fluid. In other words it has been held that they 

 are blood ferments. That this is not true is 

 shown by the fact that blood and blood serum 

 have an inhibiting effect upon autolytic action. 

 Besides, proteins which contain no blood, such 

 as egg-white, undergo autolytic cleavage. 



The study of autolytic cleavage is compli- 

 cated by the presence in many proteins of other 

 ferments such as nucleases, arginases, etc. 

 What effects the autolytic enzymes have upon 

 foreign proteins is a question of importance, 

 but one which cannot be answered at present. 

 It will be understood that I have been speak- 

 ing so far of the autolytic enzymes of the cellu- 

 lar and other proteins of the multicellular ani- 



